How to define global variables in Java?

In Java, global variables can be defined at the top of a class using the keyword static, which means outside of the class but not within methods. Global variables must be declared within a class, but cannot be declared within a method. For example:

public class GlobalVariables {
    // 全局变量
    public static int globalVar1 = 10;
    public static String globalVar2 = "Hello";

    public static void main(String[] args) {
        // 访问全局变量
        System.out.println(globalVar1);
        System.out.println(globalVar2);
    }
}

In the example above, globalVar1 and globalVar2 are global variables that can be directly accessed and used in the main method.